A low dispersion 2-GHz comparator

Abstract

A low dispersion 2-GHz comparator is an essential part of the latest automated VLSI tester by Teradyne Inc. With each new and faster CMOS logic VLSI microchips, faster and more precise comparators are needed to verify that the static discipline is being met on the many pins of the integrated circuit. As the error in the comparator is lowered, the VLSI production yield is greatly increased because of greater certainty of the measurements. The comparator described within is designed to test a variety of CMOS logic levels at the expected logic levels and rise-times of the near future. The result is a Si-Ge integrated comparator with 12psec of dispersion by detailed simulation awaiting fabrication. Index Terms-Complementary metal oxide semiconductor transistor technology (CMOS technology), very large scale integration (VLSI), application specific integrated circuit (ASIC), silicon germanium (Si-Ge), integrated circuits (IC), automatic test equipment (ATE), personal computer (PC), digital signal processing (DSP), direct current (DC), alternating current (AC), device under test (DUT), pin electronics (PE), bipolar junction transistors (BJT), complementary metal oxide semiconductor field effect transistor (MOSFET).